This kicks the player for Internal Server Error and crashes it if you continue going n that direction

18:55:36 [SEVERE] Encountered an unexpected exception ArrayIndexOutOfBoundsException
java.lang.ArrayIndexOutOfBoundsException: -128
at com.khorn.terraincontrol.bukkit.BukkitWorld.DoBiomeReplace(BukkitWorld.java:293)
at com.khorn.terraincontrol.generator.ObjectSpawner.populate(ObjectSpawner.java:86)
at com.khorn.terraincontrol.bukkit.TCBlockPopulator.populate(TCBlockPopulator.java:27)
at net.minecraft.server.v1_4_R1.ChunkProviderServer.getChunkAt(ChunkProviderServer.java:243)
at net.minecraft.server.v1_4_R1.Chunk.a(Chunk.java:797)
at org.bukkit.craftbukkit.v1_4_R1.chunkio.ChunkIOProvider.callStage2(ChunkIOProvider.java:61)
at org.bukkit.craftbukkit.v1_4_R1.chunkio.ChunkIOProvider.callStage2(ChunkIOProvider.java:13)
at org.bukkit.craftbukkit.v1_4_R1.util.AsynchronousExecutor$Task.finish(AsynchronousExecutor.java:179)
at org.bukkit.craftbukkit.v1_4_R1.util.AsynchronousExecutor.finishActive(AsynchronousExecutor.java:287)
at org.bukkit.craftbukkit.v1_4_R1.chunkio.ChunkIOExecutor.tick(ChunkIOExecutor.java:30)
at net.minecraft.server.v1_4_R1.MinecraftServer.r(MinecraftServer.java:528)
at net.minecraft.server.v1_4_R1.DedicatedServer.r(DedicatedServer.java:224)
at net.minecraft.server.v1_4_R1.MinecraftServer.q(MinecraftServer.java:485)
at net.minecraft.server.v1_4_R1.MinecraftServer.run(MinecraftServer.java:420)
at net.minecraft.server.v1_4_R1.ThreadServerApplication.run(SourceFile:849)
18:55:37 [SEVERE] This crash report has been saved to: S:\MinecraftServer\crash-reports\crash-2013-02-11_18.55.37-server.txt

Suggestion: Catch the exception and ignore it, and make a message telling you that the chunk generaton had an error. If it blocks the chunk from generating, then leave the chunk void